Compression bandages are known for use in the treatment of oedema and other venous and lymphatic disorders, e.g., of the lower limbs. An area where compression bandages are considered particularly useful is in the management and treatment of chronic wounds, such as venous leg ulcers. Achieving optimum pressure when applying compression to (e.g. leg) ulcer patients creates challenges for the clinician.
U.S. Pat. No. 3,613,679 describes an elastic bandage with a tension indicator. A series of figures forming an overall pattern is applied to the surface of an elastic bandage. When the bandage is stretched, the contours of the figures and/or their position relative to each other are altered. The degree of such altercation is an indication of the amount of tension existing in the bandage and the pressure applied by the bandage.
U.S. Pat. No. 7,956,233 refers to such tension indicator as a calibration means. As described beginning at col. 8, lines 20, “This calibration means may be visual, such as for example a set of regularly spaced pictograms printed on the bandage, or produced using a calibration system, such as for example a stencil, by the care staff who are provided with information on the recommended stretch on application. This type of stencil or the explanations necessary to manufacture it may be incorporated in a kit that includes the two support bandages that form the compression system or a selection of support bandages that allow various suitable compression systems to be produced. The principle of calibration using a stencil is the following. The stencil is generally produced by means of a cardboard sheet in which an opening has been cut that may have, for example, an ellipsoidal or rectangular shape, allowing, as will be understood, a pictogram of the same shape to be produced on the bandage. The transformation of these pictograms into circles or squares under the effect of stretching the bandage thus allows the latter to be calibrated. This principle is described, for example, in U.S. Pat. No. 3,613,679. The rectangular shape, which is easiest to cut in a cardboard sheet, is preferably used. The length and the width of the rectangle are mathematically determined depending on the stretch at which the bandage is intended to be applied. Hence if E is the stretch of the bandage on application and L the length of the rectangle that will be parallel in the weft direction of the bandage (i.e. perpendicular to the length direction of the bandage), the width L of the rectangle will be L/(1+E′). For example, to calibrate a bandage that is intended to be applied with a 55% stretch, a rectangle having a length of 4 cm and a width of 4/(1+0.55) or 2.58 cm will be used. To calibrate the bandage, rectangles of 4 cm length and 2.58 cm width are cut into a cardboard stencil. This stencil is positioned on the flat, unstretched bandage and the outline of this rectangle is drawn on the bandage, for example using a felt-tip pen.”
Various bandages with tension indicators are commercially available including for example ProGuide®, available from Smith & Nephew, Setopress®, available from Molylncke, Surepress®, available from Convatek, and K-Two®, available from Urgo Medical. In a study in 2008 (WUWHS. Principles of Best Practice: compression in venous leg ulcers. A consensus document. 2008; MEP Ltd, London) it was shown that compression bandages with visual indicators were applied more accurately than bandages without indicators. Some of these types of bandages are also self-adherent, which means they stay in place more easily.